For actuating the horizontal displacement in the two directions of the head of a diecutter machine, its positioning over the underlying die and its descent for effecting the desired cut, a number of devices are known that execute the sequence of such operations in a more or less automatic fashion. It is known, for example, a diecutter machine, made by the assignee of the present application, that is provided with a device for the automatic retrieval of the die. By means of said device, after a single impulse imparted by the operator, the head startoff in search of the die, detects it, performs the cutting descent, rises and finally returns to the starting position. Such a device, notwithstanding the undoubted technical and functional advantages, is very expensive, because of the high cost associated with all the automatisms with which it is provided, and therefore it is available to a restricted segment of the market.
Another control device of the known type and of a far reduced cost, has a sereis of push-buttons disposed on a couple of handles, associated with the head of the machine, that are gripped all the time by the operator during the entire period of operation, from the horizontal displacement of the head to its descent while the return of the head to its initial position is automatic. It is obvious that the operator, having to drive the machine with his hands on the two handles carried by the head, is compelled to physically follow the horizontal translation movement while keeping his hands in a rather uncomfortable position. All that causes physical weariness to the operator that inevitably reflects negatively on the workmanship as well as on the productivity of the machine.
With the aim to prevent such weariness of the operator, a machine has been made which control device is formed by a horizontal bar, free of being displaced horizontally and of being rotated, assembled between two pins projecting from the lateral columns of the machine. In this case, the operator, gripping with both hands the bar, may command the translation of the head to the right or to the left by simply shifting the bar to the right or to the left respectively.
Soon as the head reaches the desired position, the operator returns the bar to its initial position and successively imparts a rotation to the bar, through that the impulse for the descent of the head for the execution of the cutting operation is imparted.
Once the cutting is performed the head returns to its initial position in correspondence with the side of the frame from where it had started off.
For the sake of more convenient operation, it may be necessary, when the head overtakes the middle of the work plane while proceeding in its cutting excursions, to return it no longer to its initial position, but to a new starting position by the side opposite to the one from where it had started its last excursion. To this effect the operator, when imparting the last impulse with start from the initial position, instead of impressing a single displacement for example, to the right, to the control bar, is obliged to impart, succesively to such first displacement, a second displacement in the opposite direction to invert the horizontal direction of return of the head.
It is evident that this control system, devised to change the starting position of the pressing head, is to the least uncomfortable and scarcely rational for the operator who masters with great difficulty this system of manual control.
Moreover it should be noted that, because of the rotation that the operator must impart to the control bar to obtain the descent of the pressing head, the operator's wrists are subjected to continuous exertion for the entire working day that, besides causing an inevitable weariness, may provoke real physical troubles.